1. Field of the Invention
The invention relates to the technical field of run-time image compression and, more particularly, to a mode decision system and method for motion vector fine search.
2. Description of Related Art
FIG. 1 is a block diagram of a typical MPEG encoder system using hierarchical dynamic search. The system includes an image filter 110, a coarse motion estimation device 120, a fine motion estimation device 130, a discrete cosine transform (DCT) device 140, a quantizer 150, a variable length encoder 160, an inverse quantizer 170, an inverse DCT (IDCT) device 180 and a motion compensation device 190.
A frame 100 passes through the image filter 110 to thus generate a low resolution frame. Next, the coarse motion estimation device 120 performs coarse search on the low resolution frame and sends the result to the fine motion estimation device 120 for further performing fine search on the frame 100 upon all modes, thereby finding a best dynamic search result. However, such a way requires much operation time to complete the fine search, and thus in an application of run-time image compression, the fine search may not be completed in a fixed time.
Therefore, it is desirable to provide an improved method and system to mitigate and/or obviate the aforementioned problems.